Life is not possible without water. Water is a primary necessity of life. The water ingestion of birds varies widely. Canaries and wild birds need proportionally more liquid by nature than small tropical birds and Australian parakeets, for instance.
Accordingly, birds must be able to determine themselves under all circumstances how much free moisture (water) they want to ingest, i.e. by ingesting more or less fresh drinking water.
They can do this only if the bird lover does not provide too much moisture-rich feed, such as sprout seeds, vegetable feed, fruit, etc.
Both in cold or warm weather birds must get fresh drinking water daily. The drinking water can also be a source of infections when food residues or excreta wind up in the water.